Journal of Horticultural Sciences

R. M. Bhatt ¹, N. K. Srinivasa Rao ¹, A. D. D. V. S. Nageswara Rao ¹

Affiliations
1 Division of Plant Physiology and Biochemistry, ICAR-Indian Institute of Horticultural Research, Hesaraghatta Lake Post, Bengaluru - 560 089, IN

Abstract

A study was conducted to evaluate the effect of exogenous application of glycinebetaine (GB) on physiological response in hot-pepper (Capsicum annuum L. vs. Arka Lohit and Pusa Jwala) under water stress. Glycinebetaine was applied to seeds as well as plants through foliar applications. Water stress affected considerably the morphophysiological parameters in both the cultivars. However, in glycinebetaine (GB) treated plants, plant height, leaf area (LA), flower and fruit number and total dry matter (TDM) were greater compared to the untreated stress plants (T4) under water stress. Glycinebetaine application enhanced the photosynthesis (P_N) in water deficit experiencing plants, mostly due to a greater stomatal conductance (g_s) and carboxylation efficiency of CO₂ assimilation. In both the cultivars after 12 day of stress, the P_N decreased from 10.1 to 1.0-1.3 μ mol m^-2 s^-1 in untreated stressed plants (T4), while in the treated stressed plants P_N had reduced to 2.0 - 3.0 μ mol m^-2 s^-1 (T1 - T3). The application of GB increased the WUE in both the cultivars. The better WUE in treated plants of hot-pepper under stress was attributed to the improved P_N. The higher per plant yield in the GB applied plants under stress in both the cultivars associated with higher P_N rate, gs and WUE in treated plants. Though there was an increase in P_N rate, WUE and plant yield in the treated plants (T1 - T3), the better results were found in the plants (T2) where seeds were treated and foliar application was given at the time of imposing stress.

Keywords

Glycinebetaine, Hot Pepper, Photosynthesis, Stomatal Conductance.

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R. M. Bhatt ¹, Rashmi ¹, A. D. D. V. S. Nageswara Rao ¹, R. H. Laxman ¹, T. H. Singh ¹

Affiliations
1 Division of Plant Physiology and Biochemistry, Indian Institute of Horticultural Research, Hessaraghatta lake Post, Bangalore - 560 089, IN

Abstract

A study on seed germination and seedling growth was conducted with five cultivars of Solanum melongena L. (cvs. Arka Nidhi, B.P.L.H.-1, Arka Neelakanth, Arka Keshav and Mattu Gulla) and a wild species Solanum macrocarpon L. under different levels of osmotic potential induced by polyethylene glycol (PEG 8000). Germination declined progressively in response to decreasing (more negative) water potential, and no germination was found beyond - 0.4MPa in any of the cultivars/species. Except for cvs. Arka Nidhi, B.P.L.H.-1 and Mattu Gulla, no germination was seen at -0.4MPa Cultivar Arka Neelkanth failed to germinate under any of the osmotic concentrations tested. Response in term of ischolar_main growth was better in Arka Neelkanth, followed by Arka Nidhi and B.P.L.H.-1, upto transfer from different levels of osmotic potential to Control (0MPa). Germination of primed seeds within 24h indicates that many processes leading to normal germination would have been completed during the priming process itself. In contrast to germination, growth extension in radicle was less sensitive to water stress.

Keywords

Brinjal, Germination, Osmotic Potential, Water Stress.

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